1. Field of the Invention
The present invention relates to a disc recording and/or reproducing apparatus in which an information signal of a record and/or a reproduction is made possible with respect to a disc shaped recording medium and more particularly relates to a disc recording and/or reproducing apparatus suitable for being used in an image pickup device which uses a disc shaped recording medium as an information recording medium.
2. Description of the Related Art
There has been known, for example, an apparatus described in a patent reference 1 as a conventional disc recording and/or reproducing apparatus which uses a disc shaped recording medium as a recording medium. In the patent reference 1, there is described about an industrial television camera apparatus in which a television camera is installed in a camera case attached with a defroster glass on the side of the front portion thereof.
In an industrial television camera apparatus in which a television camera is installed in a camera case mounted with a defroster glass for securing a visual field on the side of the front portion thereof, the industrial television camera apparatus described in the patent reference 1 has a feature that it comprises a temperature sensor and a moisture sensor which are provided on the side of an inner face of aforesaid camera case and on the side of an outer face of the camera case touching the ambient air directly for detecting temperature and moisture on the side of an inner face and on the side of an outer face respectively; a dew removal equipment and a dew prevention equipment which are provided on aforesaid camera case for carrying out a dew removal and a dew protection on aforesaid defroster glass; and a control means for judging whether or not aforesaid defroster glass is in a dew condensation condition or in a condition that a dew is formed easily based on signals from aforesaid temperature sensor and aforesaid moisture sensor and for operating aforesaid dew removal equipment or aforesaid dew prevention equipment with respect to afore said defroster glass when it is judged that the defroster glass is in a dew condensation condition or in a condition that a dew is formed easily.
According to the industrial television camera apparatus having such a constitution, it is possible to remove a water droplet or the like dew-formed on the defroster glass certainly and at the same time it is also possible to plan a protection of a dew condensation onto the defroster glass.
However, in case of such an industrial television camera apparatus, it is constituted such that temperature sensors and moisture sensors are provided on both faces of the inner face and the outer face of the camera case respectively and it is judged whether or not the inside of the camera case is in a dew condensation condition based on those detection results, so that not only a lot of detection sensors are necessary but also it is necessary to carry out a predetermined operation process based on the detection signal obtained from the respective detection sensors and thus there was a problem that a device for judging a dew condensation condition becomes complicated.
As a result, for example, a problem of a cost increase caused by an increase of the number of parts, lowering of workability caused by an increase of the number of assembling processes or the like is to occur.                [Cited Patent Reference 1] Japanese Laid-Open Patent No. 7-107349        